1. Field of the Invention
The present invention relates to wind power utilization devices, and more particularly to a high efficiency wind power machine suitable for large scale, commercial utilization.
2. Description of the Prior Art
As fossil fuels become more expensive, and as the inescapable pollution hazards of nuclear power become more and more apparent, considerable interest has turned toward utilization of pollution-free natural energy sources, such as wind power. Wind power has been utilized for centuries as a means of propelling vessels across the sea and for operating pumping systems of the type utilized in Holland and other countries. For many years technological developments have slowly improved the efficiency of wind utilization apparatuses, although cheaply available fossel fuels have in the past all but eliminated the need for research into effective wind power conversion systems. Now that the age of cheap fossil fuels has past, research into improving the efficiency of wind power conversion systems has again begun in earnest. A number of improvements in wind power conversion systems have recently been disclosed, as for example in U.S. Pat. No. 4,035,658 disclosing a high-power wind turbine with kinetic accumulator. The apparatus disclosed in this application includes a modular wind power conversion system employing turbine-type blades and provides a technique for storing the power generated by these blades. A related development is disclosed in U.S. application Ser. No. 624,385, filed Oct. 21, 1975, now U.S. application Ser. No. 935,504, filed Aug. 21, 1978 which relates to a guided flow wind power machine which employs unique power conversion modules having fan blades of a generally tubular configuration. This device also includes a technique for storing energy generated by the fans. U.S. Pat. No. 3,970,917 closes an energy storage and DC to AC conversion system which is particularly suited for use with the previously mentioned wind power conversion systems.
Although the systems disclosed in these various applications constitute a significant improvement over earlier technological developments, it has been discovered that further improvements in wind power conversion efficiency are attainable by further technological innovations. For example, it is known that rotary turbine blades are somewhat inefficient in that the wind pressure is much less effective at the blade hub and tips than at the central portion of the blade, and also in than in a large surface area comprised of circular rotating blades, only 78% of the total area can be occupied by the blades, reducing the effective power conversion area of a given sized structure.
Guided flow structures having tubular fan arrangements of the type disclosed in application Ser. No. 935,504 are somewhat more efficient than circular blade arrangements in that a somewhat more uniform power conversion efficiency is permitted over the blade surface exposed to the impinging wind and in that a somewhat greater efficiency in useful percentage of total frontal area is provided. Nevertheless, greater improvements in efficiency have been sought for reducing the cost of producing commercial electrical power from wind power conversion units.